1. Field of the Invention
This invention relates generally to a method and apparatus for cutting only the base sheet of a laminated sheet, such as an adhesive tape which comprises an adhesive-coated base tape to which a backing sheet is applied.
2. Description of the Related Art
Tape printing apparatuses used for printing text and graphics to a tape-like sheet material have become widely available in recent years. The tape used in these apparatuses is typically an adhesive tape comprising an adhesive-coated base tape to which a backing material has been applied. After being printed on the surface of the base tape, the tape is typically cut to certain dimensions for use as a label. When the printed tape, i.e., label, is then used, the backing tape is peeled off and the adhesive-coated label is applied to the desired part of the object. Because of the difficulty of peeling the thin label from the backing paper, these labels are often cut only partially relative to the thickness of the tape. More specifically, only the base tape is cut and the backing tape is left uncut, making it easier to separate the label from the backing paper.
A cutting method and apparatus of this type are described in Japanese utility model patent JIKKAI SHO57-98837 (1982-98837). This cutting method and apparatus describe a press-cutting method whereby a cutter is lowered vertically to the adhesive tape with the adhesive tape held stationery on a hard cutting bar.
With this conventional cutting method, it is necessary to adjust the cutting depth of the cutter with precision ranging from several microns to several ten microns because of the need to cut only the tape (and adhesive) without cutting the backing paper. Correspondingly high precision is therefore required in the construction and control of the apparatus, and maintaining the stability of the cutting precision is a common problem.
In addition, variations in the types and thickness of the materials used even in the same type of adhesive tape make it impossible to assure consistently reliable cutting depth precision even assuming the apparatus is constructed with sufficient precision.
Therefore, it is an object of the present invention to provide a laminated sheet cutting method and apparatus enabling consistent partial cutting of a laminated sheet without requiring high precision control of the cutter cutting depth.